Automatic cutoff valve



2 Sheets-Sheet l J. D. FORE Sept. 1, 1953 AUTOMATIC CUTOFF VALVE FiledJune 24, 1949 Sept. 1, 1953 J. D. FORE AUTOMATIC cUToFF VALVE 2Sheets-Sheet 2 Filed June 24, 1949 RQR INVENTOR R R l- VII Y .w .Wfl

Patented Sept. 1, 1953 UNITED STATES PATENT OFFICE AUTOMATIC CUTOFFVALVE John D. Fore, San Angelo, Tex.

Application June 24, 1949, Serial No. 101,171

2 Claims. 1

This invention relates to hydraulic fluid systems and more particularlyto check valve means leading from the master cylinder of an automobilebrake system to the respective brake cylinders.

A main object of the invention is to provide a safe and improvedautomatic cut-01T valve device for use in automobile hydraulic brakesystems, or other hydraulic systems, said device being constructed forlong service-free life, being arranged to automatically compensate fornormal wear, expansion and contraction of metals under temperaturechanges, and arranged to provide the user maximum brake protection withminimum possible risk of braking failure due to improper operation ofthe valve itself when placed in the brake line leading from the mastercylinder to one or more of the brake cylinders of a motor vehicle, saidcut-off valve operating automatically to close and shut off iiuid fromthe master cylinder to any portion of the brake system containing a leakor rupture in response to application of pressure to the brake pedal.

A further object of the invention is to provide an improved automaticcut-off valve for use in the hydraulic brake system of a motor vehiclewhich operates to automatically check the escape of liquid when thebrake pedal is depressed in the event that a leak occurs between themaster cylinder and one of the brake cylinders of the vehicle, saidcut-off valve including signal means for providing an indication as towhich portion or" the brake system is leaky whereby the defectiveportion may be readily located and repaired.

A still further object of the invention is to provide an improvedautomatic cut-off valve for use in the brake lines of a motor vehiclebetween the master cylinder and one or more of the brake cylinders, thecut-oil valve being very simple in construction, easy to install, andbeing very easy to maintain in operating condition.

A still further object of the invention is to provide an improvedautomatic cut-01T valve for use in a hydraulic fluid system between themaster cylinder and one or more of the subsidiary cylinders of thesystem, said cut-oir valve including automatic equalizing means toprevent excessive back pressures from being built up in the liuid lines,and being arranged so that operation of the subsidiary cylinders may beobtained even in the event that portions of the automatic cut-01T valvemay be jammed or frozen.

Further objects and advantages of the nvenright iront brake line isshown at 2l.

tion will become apparent from the following description and claims, andfrom the accompanying drawings, wherein:

Figure 1 is a longitudinal vertical cross sectional view taken throughan improved automatic cut-off valve for a hydraulic brake systemconstructed in accordance with the present invention.

Figure 2 is an enlarged elevational detail View of an alternate form ofmovable valve element which may be employed in the cut-orf valve ofFigure 1.

Figure 3 is an enlarged elevational detail View of another alternateform of movable valve element which may be employed in the cut-off valveof Figure 1.

Figure 4 is a schematic diagram illustrating in diagrammatic fashion ahydraulic brake system employing cut-off valve members in accordancewith the present invention.

Figure 5 is a side elevational view of a bracket member employed tosecure the cut-off valve of Figure 1 to the vehicle frame.

Figure 6 is a top plan view of the bracket member of Figure 5.

Figure '7 is an end elevational View of the bracket member of Figure 5.

Figure 8 is a fragmentary longitudinal cross sectional view takenthrough a portion of a modied form of automatic cut-01T valveconstructed in accordance with the present invention.

Referring to the drawings, and more particularly to Figure 4, it will beseen that II designates a conventional master cylinder operated from thebrake pedal I2 of a motor vehicle. The outlet conduit I3 of mastercylinder II is connected to respective front and rear wheel brake linesI4 and I5. Designated at I6 and Il are the left front and right frontwheels of the vehicle. Designated at I8 and I9 are the left rear andright rear wheels of the vehicle. The left front brake line is shown at20 and the Designated at 22 is a rst automatic cut-off valve. Therespective brake lines 20 and 2| are connected to the respective ends ofvalve 22. The iront brake line I4 is connected to the intermediateportion of Valve 22. A similar automatic cut-off valve 22 is providedbetween the rear brake line I5 and the respective rear wheel brakelines, shown at 23 and 24.

Each of the valves 22 is secured to the vehicle frame by a bracket 25illustrated in Figures 5, 6 and 7, said bracket comprising alongitudinal body portion 26 formed with bolt holes 2l and 'bersi39, 39.

213. The ends o body portion 26 are formed with opstanding opposingarcuate clamping fingers 29 adapted to embrace the body of the valve 22and to clamp same by means of fastening bolts passing through the endsof the lingers 29, 29, said ngers having apertured end tabs 3| receivingthe bolts.

Referring now to Figure 1, the automatic cutoff valve 22 may compriseazgenerally cylindrical body 32 formed at .its intermediate portion witha conduit fitting 33 to which the master brake cylinder fiuid line I4 orI5 may be connected. Threaded through the wall of body 32 opposite inlettting 33 is an inwardly projecting stop screw 34. Threadedly secured ineach end of body 32 is a flanged plug 35, a deformable ring gasket 33being interposed lbetween the ilange of the plug and the end of body 32to'provide a iiuid tight seal. Each plug 35 has an axial bore 3i.Connected to -the plugs by means of threaded bushings 38 .are Ttherespective brake cylinder conduits, `such Vas the :conduits 2B and 2ishown in Figure l.

Slidably mounted -inthercylinderZare the respective oppositely facingcup-'like piston mem- The end awall 'of each Vmember 3911's formed with:an axial :bore F49. Threadedly .secured in each member 39 is a ringmember 11|. Axially positioned in each :member '39 isa movable valveelement 542 passing through the associated ring member 4l.. IAt `its:inner eend 'the valve element 42 is formed with an annular flange 43.4lilncircling `the :valve element .and bearing between iiange-s43.andrthe associatedring member `4l is a conical :spring 2144, biasing:flange 43 against the end wall of piston member -39. At its outer end,veach valve :element 42 is .formed with a cupped headz4i5 in which issecuredfa-valve ball46. The inner end of leach YplugSii 'is :formed witha boss 4l, said boss Vbeing Iformed with va spherical valve seat .43'adapted to 'receive the valveball 4S 'in sealing'relation thereon. -A`coiled spring 49 is seated :around each boss 41, said springbearing on"theassociated ringfmember 4l and biasing the associated piston member39lfinwardly of the cylinder 32. Each 4Valve element 42 is formed with a`passagel) openingatiitsintermediate portion and vextending through theshank of the valve element ito 4the .inner end of said element whereinis positioned fa `ithreaded sleeve I. 'The `passage .150 is `enlargedadjacent sleeve 5l and containsa springpressedlball-check valve 52closing oir the passage 59 to .outward iiow of uid `from sleeve 51towa-rd :the-reduced porti-on or" the passage but allowing reverse flowthrough the passage from the spacefaround the Valve element toward theinner-endcf said :valve element. As shown in Figure 1, the .spring 44holds ange 43 in abutment with ther-end Wall rof piston member 39,whereby 'the sleeve .55| is 'in communication with axial 'bore '4.0.Spring 44 biased .against flange 43, OfpartALnO't-onlyiprevents anyfluid from returning from zthe isubsi- Adiary cylinder fluid lines *2UYand :2| through Apassage 49 but also performs 'the dual purpose :offorming :a check valve 4outof :flange 43, permitting only the iiow offluid underjpressure towards the fluid lines 29 and 2i, .and inconjunction with spherical vvalve seat 148 :and boss :47 :permits themovable sealing element .46 to be resilient the istud is an insulatingcap E2.

v.ing on the shoulder defined .at the base or" the vstud is a Ihexagonalwasher F59 slidable in the enlarged cylindrical bore portion 55.Threaded on each boss 53 is a cap 60. Threaded inside cap 60 is aninwardly flanged ring 6|. Threaded on Encircling cap 62 isa coiledspring 63 bearing between washer59 `and the inwardly extending flange of:ring 16|,

biasing detent pin 53 downwardly. Axially secured in the top end of eachcap 60 and insulated therefrom is a terminal bolt 34 having an integralcollar 65 cooperating with a nut 63 -to :rigidlyrastenthe bolt to thecap. Positioned iinzthe capriis a downwardly .facing cup member '611havinganinsulatingliner 68. The `lower end or :bolt 64 -extends :throughVthe r4end Vwall of `cup member 6l and is insulated therefrom. Saidlower 'end :carries :a -pontact disc -69. Designated :at 19 sis acontact jplate bearing on the end -o cap 152 yand -biased intoengagement therewith by a icoiled spring *1l seated on -plate 19 arounda -central-stud'formed thereon and bearing'ondisc ,59. The-space :in capE0 between cup member -51 'and the top ofthe Ycap 60 is lledwith sealingAmaterial :12. vSaid sealing material .may be compressed :by adjusting'the positionof ring 6l vup :wardly in 'thefcap 60.

.As shown -:in :Figure 4, each terminal vbolt 64 -is .connected bya wire13 rfto one terminal of an indicatnr lamp T4. The other .terminal ofeach `lamp vis.connected to the positive pole of -a bat- -tery 115. Thenegative pole .of the 'battery is grounded. The valve22fisalso grounded.There- Flore when-'contact plate 10 4lis allowed to engage lring 6|'theassociatedlamp 4 becomes energized through a circuit comprising thepositive termi- Lnal lof battery 15, the :signal lamp 14, wire 13,vterminal bolt 64,'spring 'H ,plate 10 yand Vring 6| rto ground.

From `Figure l it will be seen that normally pin 56 is -held in elevatedposition by engaging the wall v01E-piston 39, as seen at the left sideof 'Figure "1. 'When the brake Alines are in normal operating condition,depression of the brake pedal-Will cause the master cylinder toforcernore .brake fluidinto the valves 22 through the inlet conduits 39.LThe `fluid will enter the space be- `tween the pistons 39, 39 and causethe pistons to move :toward 'their Usealing oli positions, but as soonas lthe wheel brake cylinders force the brake shoes against the brakedrums, the back pressure becomes vequal to vthe vapplied pressure fromthe master cylinder andthe pistons 39 stop before they `reach theirlocking positions. Upon release of pressure 'on the master cylinderside, the pistons 39 are `pushed back to vtheir starting positions'against stop screw 34. Because bores 49 vare small in area incomparison to the area of be flocked vfor any `reasonin their openpositions (as they would be to install them and bleed the lines) Asofthat the valve iin fitse'lf iwould not =cause the loss of brake uid fedthrough it. Bores 40 are normally held closed by the flanges 43 and theaction of conical springs 44 thereon, preventing the loss of much fluidshould a line break before pressure is applied, and at the same timeprovide a large bypass channel when pressure is applied, thus giving agreater degree of safety than could be had by a small normally openbypass channel.

If one of the brake lines is broken or leaky, the back pressure on theassociated piston member 39 will be relatively small and the pistonmember will be therefore moved outwardly under the applied brake luidpressure, causing the ball valve element 46 carried thereby to engage inits seat 48 and close ou the defective brake line. 'Ihe valve is sodesigned that the sealing element 46 and seat 48 engage only when thereis any abnormal movement of the piston. The resilient self-aligningsealing element 46 is pulled into alignment with its fixed seat 48 eventhough it may have been oi alignment before pressure is applied to closethe seats. This resilient selfaligning means of the seats isaccomplished by the way the movable valve seat 46 is resilientlysupported by part 42 and spring 44 Within the enlarged cavity of thepiston body 39 permitting the resilient self-aligning sealing element 46to move in any radial direction around its axis and be pulled intoself-alignment with its fixed seat 48 by the inverted conical boss 41around iixed seat 48. This resilient self-aligning means used betweenthe movable and fixed valve seats permits the use of a far greater rangeof tolerances used in the manufacturing of the valve seats, pistons,bodies, and the body end caps. These resilient self-aligning valveseats, in conjunction with the inclined detent member, makes the valveable to automatically compensate for inaccuracies around both itsvertical and horizontal axis, and thereby permitting the valve to beadapted to the mass production and assembly line methods of productionso necessary for economical production. At the same time, the inner endof said piston member slips past the tip of the associated detent pin56, allowing said pin to be moved downwardly and forwardly by its spring63 until all slack is taken up between pin 56 and the end of piston 39,as shown at the right side of Figure l, whereby the ball 46 thereof ismaintained in sealing position thereafter until the brake line isrepaired and the pin 56 is manually reset. Because of the angle at whichthe detent pin 56 is mounted, its end moves forward as it movesdownward, thereby enabling the valve to be automatically compensated fornormal wear, contraction and expansion of the metal in the valve due totemperature variation, and small inaccuracies in manufacturing, therebyassuring the sealing of the metal valve seats under pressure and notmerely a touching fit of the seats. The ball valve element 46 is heldagainst its seat 48 under pressure not because of the strength of spring63 pushing against detent pin 56, but because spring 63 pushes detentpin 56 as far down as possible, while pressure is applied to piston 39from the master cylinder. Then when the iluid pressure is released frompiston 39, said piston tries to return to its open position, but due Atothe square end of piston 39 and the shape of the end 5l of detent pin56, the sidewse back pressure locks the detent pin instead of pushing itupward, thereby locking the valve in its sealing position underpressure. Under the conditions represented at the right side of Figurel, the

contact plate 10 engages the ring 6|, causing the associated signal lamp14 to become energized.

After the defective brake line has been repaired, the pin member 56 maybe reset by removing the associated cap and manually lifting theinsulating cap 62 secured to the top end of said pin member. The spring44 associated with the piston member 39 formerly locked by the pinmember then returns the piston member to normal position.

An adjustable screw 16 is provided in the Wall of the body 32 adjacenteach boss 53 which may be manually turned to project into the body toprevent the piston member 39 associated therewith from moving to closingposition during the bleeding of the brake lines subsequent to the repairoperation. Screw 16 is normally covered by a headed screw ll, said screw'l1 being readily removable to aord access to screw i3.

Under normal operative conditions of the brake lines, the building up ofexcessive back pressures in said lines for any reason is prevented bythe provision of the ball check valves 52 which alloit7 ow of brakefluid from the lines toward the master cylinder.

The movable valve element 42 may have a ball tip, as shown at 46, inFigure 1, a sharp conical tip, as shown at 5l' in Figure 3, or atruncated conical tip, as shown at 'i8 in Figure 2, or some combinationof all three.

The inclined position of the detent pin affords a substantial forwardmovement of the tip of the pin as it moves downwardly, whereby loosenessof locking engagement is avoided, automatically compensating for normalwear, expansion and contraction of the metal due to temperature changesand permitting parts to be machined and assembled at a substantiallybroader margin of working tolerances, thereby making the valve lesscritical in adjustment and giving it a safer and longer trouble-freelife.

In the embodiment of the invention shown in Figure 8, the valve body 32contains the respective axially bored pistons "i9, each piston havingsecured to its inner end a plug member $39 and to its outer end a plugmember 3 i. Plug member is axially bored at 82 and contains thespringpressed ball check valve 63 preventing return flow of uid towardthe master cylinder. Plug member 8| is formed with a large cylindricalpassage 84. Designated at is a valve element disposed axially in plugmember 3| and formed with a head 86 located in a cavity 81 formed in thepiston body. `Secured to the outer end of element 35 is the block member68 in which is secured the valve ball 96. A conical spring 9| encirclesthe element 85 and bears between block 83 and plug member 8|, biasinghead 66 against the inner wall surface of the plug member. The innerbore of the plug member is further recessed at 92 Ato define a passagefor brake iluid into passage 84 past head 36. The piston body 'I9 isformed with an annular groove 93 into which the tip of the detent pin 56may engage to lock the piston 19 in sealing position responsive to theapplication of braking pressure when the back pressure on the pistonfails due to a broken or leaky brake line.

Ball check valve 83 prevents loss of any great amount of fluid shouldany line be broken before pressure is applied to the master cylindercausing the valve to close. The use of ball check valve 83 permits theuse of a larger axial valve passage, shown at 94, than would otherwisebe feasible, and will permit enough fluid to pass @spaanse through sothat the operation lof vthe brakes lis :not infected even whenthe pistonfreezes in -open position. rThis :check valve :83 is also used forinstalling .and .bleeding the lline while .installing the valve, ,asWell as for :equalization of pressure :between 'the master cylinder andthe wheel -lcylinders. VSpring Srl holds the rear face `of head 8E lawayfrom the 'end opening of -bore 94, allowing iiuid to now around -head 86during normal operation of the brakes. When a leak develops 'in thebrake lines, operation of the brake pedal causes the ,piston 19 to :moveball 9% Vto seating position, the head fBB being then in sealingrcontact with the Wall zof recess 8-1 around the .opening of bore `$34..At the same time, the locking pin '56 moves downwardly into the locking.groove 93.

Due tothe vangular.position 4of the locking pin, the valve ,piston isheld sealed under pressure even after pressure .has ,been released fromthe master cylinder. As above .mentioned the -angular position of thepin `and the .conical :shape of .its tip .enables :a good:metal-to-metal seal to be obtained .without requiring any .great amount.of precision in making and adjusting 4the -valve, 'as would be.required in a right-.angularly positioned locking pin.

While certain specic embodiments of an automatic cut-oir valve for usein hydraulic uid systems have been disclosed in the foregoingdescription, it will be understood that various modifications withinVthe spirit ofthe invention may occur to those-skilled in the art.Therefore, it is intended that no limitations be lplaced on the:invention except as deiined by the scope of the appended claims.

What is claimedis:

'1. An automatic cut-oil" valve for use in a hydraulic fluid system'comprising a master cylinder, .subsidiary cylinder and rst cylinder,conduit means connecting said 'airst cylinder tothe master cylinder ofthe system, additional conduit means connecting 4said A.iirst cylinder.to the subsidiary cylinder, a pistoninsaid iirst cylinder, said piston.being formed With a passage therethrough, said passage normally heldclosed by spring pressed :check valve, said ichecl: valve permittingonly the `flow of :uid under pressure towards said adidit'ion'al conduitmeans, .a sealingelementcarried by said'piston and .-sealinglyengageable in a seat connected to :said additional conduit meansresponsive to abnormal .movement of the piston to- `Ward said seatspring means opposing'such .movement, .and .an -inclined spring pressed4detent member Iextending.slidably 4through a wall of said rst cylinderand normally engaging the side of said piston, `the detent member beinglockingly v'engageable behind the piston 'when said piston has :beenmoved into sealing position with respect 'to 4said seat.

2. An automatic cut-off valve for :use ina hydraulic iuid systemcomprising a master cylinder, Vsubsidiary cylinder and iirst cylinder,conduit means Yconnecting said -iirst cylinder to .the master cylinderlof .the system, 'additional conduit means connecting said first`cylinder to the subsidiary cylinder, apiston in said rst cylinder. saidpiston being formed `with a passage therethrough, a sealing velementcarried bysaid piston and sealingly engageable -in a seat `connected to.said additional conduit means responsive 'to abnormal movement of thelpistontowardsaid'seat, 'spring means opposing such movement, resilientself .aligning vmeans acting between said sealing `element 4and saidseat, .said resilient self laligning means normally holding said sealingelement sealingly against -the portion Vof the piston adjacent thepassage therethrough permitting .only the how of fluid under Ipressuretoward said additional conduit means, said sealing element being formedwith -a second 4passage communicating with the piston passage and`opening laterally -of the element, a normally ,closed check `valve insaid second passage allowing -only return flow of iiuid under 'pressurethrough piston passage `toward Ysaid conduit means, an inclined springpressed Ydetent member extending slidably through a Wall oisaid rstcylinder and normally .engaging the side .of said piston, thedetent'member being lockingly engageable ybehind the piston when saidpiston has been moved into sealing position with respect .to-said seat.

JOHN D, FORE.

References Cited in the 'file 0f this vpatent UNITED STATES PATENTS

